March 23, 2009 The next generation of Super Broadband DSL is just around the corner. Swedish Telecommunications giant Ericsson has demonstrated 500-Mbits/s transmission rates over copper cabling by using new crosstalk cancellation or "vectorized" VDSL2 based modems. The data rate is over 20 times faster than the fastest ADSL2 services currently on offer in most countries. With products using the technology likely to be available by the end of the year, this will open up the possibility of broadband services such as video-on-demand over IPTV networks.

Ericsson says this VDSL2 technology will be cost-effective for very high speed services such as HDTV and will also help faster rollout of 4G broadband mobile phone services when used for backhaul of mobile base stations .

Crosstalk cancellation improves VDSL2 performance by reducing noise originating from the other copper pairs in the same cable bundle. Vectoring technology also decouples the lines in a cable, substantially improving power management, which can reduce power consumption.

Ericsson's demonstration was over a relatively short distance of 500m and was achieved by bundling six lines (twisted pairs) into one which showed aggregated rates of above 500Mbit/s. While few existing homes have six lines, vectoring technology can still offer a significantly improvement on current ADSL2 technology where the maximum advertised speed of 25Mbit/s is only available within 600 meters of the exchange with less than half that speed available only 2 kilometers from the exchange. Because ADSL2 transmits and receives data using tones most limitations are due to line noise and cross talk interference. The new VDSL2 standard, expected by the end of 2009, addresses this resulting in extended high speed broadband reach from each exchange potentially making broadband services such as IPTV accessible to more uses.

Paul Evans